Process and apparatus for distilling liquids



June 25, 1946. w. R. P. DELANO 2,402,737

PROCESS AND APPARATUS FOR DISTILLING LIQUIDS Filed Nov. 12, 1942 2 Sheets-Sheet 1 IN V EN TOR.

I WILL/AM RJ. DEL/3N0 BY 16 \Z QT 227m June 25, 1946. w. R. P. DELANO 2,402,737

PROCESS AND APPARATUS FOR DISTILLING LIQUIDS Filed Nov. 12, 1942; 2 Sheets-Sheet 2' IN V EN TOR.

WILL/AM R. F! DEL/7N0 BY A TZUM UNITED STATES PATENT OFFICE it PROCESS AND APPARATUS FOR DISTILLING LIQUIDS William R. P. Delano, Syosset, N. Y., assignor to Gallowhnr Chemical Corporation, New York, N. Y., a corporation of Vermont Application November 12, 1942, Serial No. 465,366

7 Claims. (Cl. 202-39) l 2 This invention relates in general to distillaon the average, several hours of sunlight per day tion and in particular to a process and apparatus in those areas of the ocean which are navigable for distilling salt water, in particular, sea water, and free from ice. I and to correlated improvements designed to ren- Accordingly, it is the general object of the presder such an apparatus collapsible and portable. 5 cut invention to provide a process nd pp tu The need of a simple and convenient method of for the distillation of liquids, in particular, sea

distilling sea water for the production of fresh water which will satisfy the objects above dewater for drinking and the like has long been scribed and meet the specifications recited.

recognized, but this need becomes increasingly a It is a further object to provide a process of important during times of war when the destruco distilling salt water by the use of solar radiation. tion of ships and airplanes at sea forces the It is a specific object of the invention to procrews to take to llfeboats, rafts and rubber floats. Vide a Simple means f r distilling a Water wh ch In such small lifesaving craft it is apparent; th t is adapted for use on small lifesaving craft.

space is limited, methods of heating either mm It further sp cific object to provide an pexistent or difficult to provide and all weight must in Daratus r istilling sea water which will be be reduced to a minimum Accordingly any collapsible, compact and light in weight, so that paratus for distilling sea water to produce fresh it n be carried in i p a es and installed as water for drinking on lifesaving craft must meet, r ular equ pment in small lifesaving craft.

inter alia, the following stringent requirements. other je t of the invention will in part be 1. The device must have a relatively low weight so obvious d W111 n p t app ar hereinafter. per unit of capacity. For example, whe th a According to the present invention, there is paratus is to be carried in aircraft and is to be P i ed a process for distilling liquids, especially used in a small rubber boat adapted only to carry for distilling sea water for the production of fresh two men, the weight of the distilling device should Water, comprising Satumting 3 1 3 of on not exceed about twelve pounds and the capacity 26 sorbem material with the liquid o be di t l d, shouldbe about two quarts per day, heating he l yer of absorbent material by solar 2. Equally important as the weight is the space radiationevaporating l uid from a surface of limitation. involved in the transportation and in the layer d nden ing the evaporated liq id.

the use of the apparatus. The device must be The liquid y e evaporated from one or both compact and occupy a small space when t in so surfaces of the absorbent layer. use, i. e., when it is carried in an airplane, and i invention also includes an appar tus for when in use, it must be capable of emcient opdistilling liquids, in p rticular sea water, comeration without occupyi g the space which would prising. in Combination, a lay r f ab orbent maotherwise be available for an occupant of the means r saturating the layer with the lif i g raft liquid to be distilled, means for exposing the layer 3. The device must be resistant to corrosion by m Solar radiation and me ns for con e liqsun, air, water and the action of the salts conum evaporated m the yertained in sea water. It must also be fabricated The Invention accm'dingly comprises a process of such material as will resist the rough handling having the Steps and relation of steps one to anincident to setting up and operating the appa- 40 and an apparatus ving the elements and ratus under adverse weather conditions in crowd- Felation 0f elements one 11 a her as set forth ed lifesaving craft. m the following detailed cription and the 4. The device should be capable of being erected P of the p l i n of which will be indiwithout tools and by unskilled persons, and should cated in the claimsbe simple in operation 4,5 For a more complete understanding of the na- The apparatus should be capable of being ture and the objects of the invention, reference fabricated without the use of critical or scarce Should be had the accompanying drawings in war materials, such as metals, plastic and the w like Figure 1 is a perspective view of one embodi- 6, The I device should operate upon source ment of the distillation apparatus of the invenof cheap, plentiful fuel without the use of an n.

open flame which would create a fire hazard. Figure 2 is another view of part of the appa- It has long been realized that a plentiful source ratus of Figure l, of fuel at sea is solar radiation for, under the Figures 3 and 3A are cross-sectional views of most adverse weather conditions, there will be, 56 certain parts of the apparatus shown in Figure 1,

Figure 4 is a perspective view of a second embodiment of the distillation apparatus. and

Figures and 6 are side elevations, in section, of a part of the device shown in Figure 4.

Figure 7 is a perspective view of a third embodiment of the device, and

Figure 8 is a view, in section, of the trough of 4 stretch the device widthwise as shown in F188. 1 and 2. In the center of the lower end of the device a second strap 21 passes around the strap 24 and the batten 26 to stretch the center downward so that any condensate will tend to collect in the depression so formed. At the lowest point of the bottom 2 (Fig. 3) there is attached a communicating bag 28 formed of waterproof sheet material which may be provided with a pouring spout 2a.

in that embodiment shown in Figs. 4, 5 and 6 the evaporation may occur from under surfaces only, while in the device shown in Figs. 7 and 8 the evaporation is from both surfaces of the absorbent layer.

Referring to Fig, 1, the simplest embodiment of the apparatus comprises a front sheet I of transparent material, a back sheet 2 of flexible non-porous sheet material, e. g. fabric, the back sheet extending on a curve over the top and having its edge 3 extending under, and being sealed to, the top edge 4 of the front sheet I. The bottom of the sheet 2 extends around the bottom and has its edge 5 extending over, and being sealed to, the lower edge 8 of the sheet I, as

To operate the device shown in Fig. 1, the liquid to be distilled, e. g. sea water, is introduced through the funnel 2|, the water flowing down the channel formed by the folded strip ID from which it is absorbed through the absorbent material I4 until this layer is saturated. During the operation water should be maintained in the channel of the folded strip I9 so that the layer I4 may be maintained in a saturated condition since this layer will act as a wick when the liquid is evaporated therefrom. Any excess liquid shown in Fig. 1. The side edges 1 and 8 of the 815 sheet I are sewn under the edges 9 and 9' of a sheet II of flexible waterproof material. e. g. fabric, which extends over the rigid side panels III of shape-retaining material, e. g. wood, and

this sheet extends through the opening and around the opposite side panel to form a back. Inside the device, there is attached to the upper side of the sheet II a coextensive layer I2 of insulating material, which has a non-absorbent upper surface, and a layer I4 of absorbent material which in this embodiment is dyed or pigmented black to render it heat-absorbent. The space between the layer I4 and the transparent sheet I forms the evaporating chamber I5 which communicates with the condensing chamber I6 which is the space between walls 2 and I8 which extend around the side panels I0 and are sewn to each other over the panels.

The layer I4 is hemmed at the top between the folded sheet I9, one end 20 of which extends through the opening I3 of the side panel I0 and terminates in the collapsible funnel 2i made of waterproof flexible material, e. g. fabric. The lower end of the layer I4 is sewn between a folded strip 22 of waterproof flexible sheet material which extends through the opening I3 and terminates in a spout 23.

The side panels ill give the device stability in two dimensions, that is through the depth and the length. To give stability in the third dimension there is provided at each end of the device a flexible strap 24 having Y-shaped ends 25 (see Fig. 2) attached by brads or otherwise to the ends of the side panels III. The total length of the strap is such that when stretched, the space betweenv the loops will be greater than the width of the device as shown in Fig. 2. Thus, to stretch the strap and thereby impart stability to the device, there is inserted inside the strap between the end loops a still batten 26 which tends to carried by the layer I4 will collect in the channel formed by the lower folded strip 22 and run out through the spout 23. To distill the liquid the device is so positioned that the transparent sheet I and therefore the layer I4 will be positioned normal to the suns rays, that is perpendicular to such rays, whereupon heat will be absorbed by the layer 20 and the liquid evaporated therefrom. Part of the vapor will condense upon the underside of the transparent sheet I since this sheet will always have a temperature lower than that of the layer l4. The heated vapor will tend to rise and pass over into the condensing chamber I6 where further quantities of the vapor will be condensed. The condensed liquid will run down and collect in the depressed base and run into the bag 28 from which it may be discharged through the pouring spout 29. If the device shown in Fig. 1 has a transparent sheet which is one square foot in area, it will produce per day in average sunlight one quart of distillate. When the device is formed of lightweight fabric and wood as above described, such device will weigh about one pound.

If desired, the device shown in Fig. 1 may be provided with a long strap at the top adapted to be passed around the neck of a person and with a second strap attached to the base adapted to be passed around the leg so that when a person sits facing the sun, the device will be stretched by means of the straps in any desired position. However, the device may be positioned on the back of a person, in which case it is preferably spaced from the bodyby means of a life preserver or wad of clothing to avoid the body heating the condensing chamber I6.

Alternatively, a foldable rack of metal or wood for supporting the device in any desired position may be readily devised by anyone skilled in the art without transcending the scope of the inven- In that embodiment shown in Figs. 4, 5 and 6, the device has a triangular cross-section and comprises a front section A, back section B, and

' a base section 0. Generally speaking, the device is placed so that the front section A is exposed to solar radiation, the evaporation occurring in the front, the condensation occurring in back section B, while the distillate is collected in the base section C. The front section A comprises preferably an outermost sheet Ia of transparent material spaced by suitable means, such as the horizontal transparent tubes 30 from a non-porous sheet 3|, so that an air space 32 is provided therebetween. The sheet a a a heat-absorbing and heat-conducting non-porous sheet material, preferably black, which is attached at its longitudinal sideedges to a coextensive sheet a of porous material, such as open mesh made of wire or fabric, the space between the layers II and 38 being occupied by a layer Ila of liquid-absorbing material, 'e. g. a pile fabric, the layer Ila being unattached to the sheets II and ll. The layer Ila is attached at its upper edge to a tube ll of a shape-retaining resilient material, for example, vulcanized fibre. The tube ll is provided with a longitudinal slot in the base through which the upper edge II of the layer Ila ispassed, the layer Ila being restrained from slipping through the slot by folding the edge to form a hem IS. The tube 3l is closed at each end but is adapted to be filled with water through hole which. is positioned under a collapsible funnel Ila made, for example, of fabric. The funnel Ila is sewn to a flap 38 which is secured to the side of the tube ll by suitable means such as buttons 38.

The back section B of the apparatu comprises pocket lIl open at its upper end H and defined by the outer wall l2 and the back wall IIa formed of a corrugated fabric, the wall l2 extending around the side and being attached, as by sewing, to the edge and bottom of the wall Fla and to the base sheet l2a. 'In the interior of the device there is provided a layer Ila of insulating material, for example kapok, which is spaced from the sheet 33 of mesh to form an evaporatlng chamber Iia by means of the ta ll of fabric, the layer Ila being of such dimension that a space is left at its upper and lower ends. If desired, a second layer of corrugated fabric ll may be sewn at its top to the insulated layer I2a and its lower edge to the base sheet l2a by means of the fabric tape 45 so as to leave a space open at the bottom, thus defining a rear condensing chamber l6a. The base lid is stitched to form a V-shaped trough l6 into which the condensed is prevented When the device is formed of a flexible nonrigid material, such as textile fabric, it is advisable to provide certain form-retaining elements to maintain the shape of the apparatus. Accordingly, side edges of the front section A and the edges of back section B may be each provided with a long pocket l1 into which a thin batten of stiff material, e, g. wood, may be slipped, the pockets being open at the bottom but closed at the top. The longitudinal collapse of'the device by the still tube il which extends across the top as shown in Fig. 4.

A third embodiment of the invention is shown in Figs. 7 and 8 in which the front section A comprises a transparent sheet lb, a layer Ilb of liquid-absorbing material enclosed between a sheet?! of heat-absorbing material and a sheet Nb of porous (mesh) materia The upper end of the layer Ilb, e. g. pile fabric, is sewn to the bottom of a trough l8 of fabric so as to form a constricted area ill. The trough and the sheet ill) and layer llb may be removed from the device for cleaning by means of slide fasteners 5i and 52 which extend acrom the top and along one side of the transparent sheet lb. The bot tom edge and the other side edge 53 of the sheet liquid may be collected. From this trough the liquid may be collected in the bag 28a formed of non-porous material having a pouring spout 29a.

Assuming that the apparatus is set up as illustrated in Fig. 4 and so positioned that the sun's direct rays are perpendicular to the front section A, the apparatus may be operated as follows:

The liquid to be distilled, such, for example, as sea water, i introduced through the funnel 2Ia while the funnel is positioned as shown in the broken lines. The liquid will distribute itself throughout the length of the tube 3l and thus wet the upper end of the absorbing layer Ila and gradually seep downward throughout the full extent of this layer. The solar radiation will heat the black sheet 3| and .by conductance heat the liquid carried in the layer Ila, thus causing some of the liquid to evaporate from the under surface of this layer through the mesh sheet 33 which supports the layer Ila. The warm air carrying the vapor of the liquid will pass upward in the chamber lba and the vapor will condense in the chamber Ilia. To promote the condensation, the pocket lIl may be filled with cool water, e. g. sea water, through the open top ll. The distillate will collect in the trough and run into the bag 28a. The cool air containing some uncondensed water vapor will pass along the base l2a and will rise again in the chamber I 5a. If the black heatabsorbing sheet 3| is formed of porous material, evaporation may occur from both surfaces of the Wer Ila.

lb are sewn to the back sheet Nb and to the side panel I llb, respectively. The side panels are rectangular or oval so that the back walls IIb and I2!) which define a pocket lllb are substantially parallel with the front wall 3Ib. The layer lib of insulating material serves to divide the interior of the apparatus into an evaporating chamber I51; and a condensing chamber lib, space being allowed at each end of the insulating layer Ilb to allow free circulation of the vapor between these chambers.

In the preferred embodiment of the device shown in Fig. 'I, the side panels IIlb'are formed of shape-retaining rigid material such as stiffened fabric, hard vulcanized fibre, plywood or the like, whereby dimensional stability is given to the structure across and along such panels. To obtain stability in the third dimension (lengthwise of the trough) suitable pocket and flat stiff batten to fit therein are provided across the bottom edge, across the one wall of the trough l9 and across the top'edge of the pocket lflb, as shown in Fig. 8. To collapse this device,

the battens are removed, and the body collapsed and folded about one of the end panels. When the device shown in Figs. 7 and 8 is made so that the width is not more than three feet and the height not over two and a half feet, it may be provided with a strap 56 to go about the neck of a person. The device may rest either on the back or on the knees and chest of the person. A second strap may be attached to the base to go around the leg or waist. Thus, in a crowded life-boat or the like, the distillation apparatus will not occupy the space of an additional seat. For operation, the person wearing the device has only to position the heat-conducting sheet 3Ib so that it is perpendicular to the rays of the sun. For distilling sea water, the trough 49 is filled with the sea water until the layer Ilb of absorbent material is saturated, and the pocket lIlb is kept filled with cold sea, water. From the pocket lllb the warm water may be exhausted through the tube 51 which i provided with a plug 58. ,The distillate is collected in the bag 28b from which it may be discharged through spout 29, by squeezing the neck of the bag and turning the bag up. In the preferred embodiment, an sheet materials employed in the apparatus are flexible sheets so that the apparatus may be collapsed and rendered compact for shipment or storage. When the batten are removed, the back section II may be collapsed against the front section It and the two sections rolled upon each other starting with the top so that the tube 2| forms a supporting core for the roll. The rolled apparatus may be encased in a container or carrying case of suitable type, not herein illustrated.

The sheet I of transparent material shown in the apparatus of Fig. 1 should be a flexible but form-retaining sheet of any suitable transparent hydrophobic material, such, for example, as a cellulose ester, a cellulose ether, or a synthetic resin. Preferably, there is employed for this sheet material a transparent plastic which is permeable to visible and infra-red radiation such, for example, as cellulose acetate or cellulose aceto-butyrate. It is to be understood that the transparent sheet shown in Fig. 4 is employed solely for trapping a layer of warm air next to the surface of the heat-conducting layer 31. When evaporation takes place only from the underside of the layer It, the transparent sheet may be omitted.

For the heat-conducting layer 3Ia or 3 lb there may be employed any one of the following:

(a) A thin sheet of material which is capable of being rolled upon itself and which may be formed of copper, brass, nickel, aluminum and other non-corrosive metals.

(b) A layer of nonporous textile fabric preferably a layer of closely woven fabric which has been dyed black or impregnated with carbon black which renders it heat-absorbing. When this fabric layer is to be non-porous, it is preferably sized or coated with a waterproofing composition comprising a resin, a cellulose derivative, wax, rubber, etc.

(o) A layer of textile fabric formed in whole or in part of metallic fibres or yarns by which its heat conductivity is increased. In other respects this layer should have the characteristics enumerated under b.

For the layer l4 of absorbent material, there may be employed alaycr of pile fabric, a layer of inter-felted fibres such, for example, as textile felt or a soft, porous paper which has been sized with a water-insoluble substance such, for example, as casein, a resin or a cellulose ester which does not disintegrate when Wet. Since layer M should be capable of being washed and wrung out, it is preferably formed of a material having a sufficient tensile strength for this purpose, that is, a textile fabric or felt.

For the sheet 33 of porous mesh material, there may be employed an open mesh textile fabric formed of high tensile yarns or a mesh of woven non-corrosive wire. Since the layer it of absorbent material, when saturated with water,

will be almost wholly supported by the sheet 33, this sheet must be of such strength as to .support the weight of the layer l4.

The sheet II of insulating material may be formed of felt, paper, viscose sponge, spun glass or rock wool, or any other suitable flexible insulating material. The upper surface of the layer l2 which will be exposed to the heated vapor should be rendered non-absorbent as by coating the surface with an hydrophobic cellulose ester, cellulose ether, synthetic resin and the like.

All other parts of the apparatus, such as the any flexible non-porous sheet material such, for example, as textile fabrics, felt or paper. Such materials should be stiffened and rendered waterproofby impregnating or coating them with.

an hydrophobic cellulose ester, cellulose ether, synthetic resin and the like. In general, all such sheet materials should be water impermeable. However, to promote the cooling of the water held in the pocket 40, the wall Ila may be made of a porous material so that water will evaporate from its surface.

It is understood that various changes can be made in the apparatus and in its mode of operation. In particular, for stabilizing the shape of the device when it is made largely of flexible nonrigid material, suitable folding frames of wire or wood may be readily devised by those skilled in the art without transcending the scope of the invention. More or less permanent'frames may be readily devised from flag poles, lances, bayonets, rifles, boat hooks and other available rigid members. To facilitate the use of such framing elements, the device is preferably provided with strong cords or tapes 52 sewn at the corners so that the device may be stretched upon the rigid frame. It is obvious that the device is not limited to any particular size, nor is it limited to use at sea or in life-saving craft, but may likewise be used in the desert or anywhere for the distillation of non-potable water of all kinds.

Accordingly, the present invention provides for the first time a light-weight portable distillation apparatus which can be fabricated free of scarce metals and plastics so that the weight per unit of capacity can be kept extremely low, for example, to less than 2 pounds per quart of liquid distilled in 12 hours. The present device is small in size, readily collapsible to a compact unit and easily reconstructed without tools or mechanical skill. The device is especially adapted to be carried in aircraft as a part of the regular equipment of emergency life-saving rafts or floats. Since it may be fabricated of tough fabric or paper and the like, it is resistant to corrosion and withstands rough handling. The fact is that it requires no solid, gaseous or liquid fuel, it is economical to carry and operate and does not create a flre hazard in storage or use.

Having described my invention, what Iclaim as new and desire to secure by Letters Patent is:

1, Apparatus for distilling liquids by solar radiation, comprising ,an absorbent layer of material movable into a position normal to the sun's rays, a containerextending along the upper edge of said layer and formed with a slot therein into which said absorbent material extends to receive liquid from the container, and means for conducting vapor from said absorbent layer to an area shaded from the sun's rays for condensing said vapor.

2. In solar distillation apparatus an enclosure formed of flexible material and having a flexible window therein, a layer of flexible absorbent material located within said enclosure and connected thereto, means for supplying liquid to be distilled to said layer, rigid members connected to said enclosure, and extending along opposite edges thereof, and means for holding said enclosure and absorbent material extended for use including elements extending from one of said rigid members to the other and of such length as to place said enclosure under tension from 'side to side when in place, said elements being base sheet 42 and back walls may be formed of 1 separably connected to said rigid members and to said enclosure, whereby said apparatus may be collapsed for storage.

3. In solar distillation apparatus, an enclosure formed of flexible material and having a flexible window therein, a layer of flexible absorbent material located within said enclosure and having its edges connected thereto, members connected to said layer and enclosure and located adjacent opposite edges thereof, said members being rigid and serving to hold the edges of the enclosure and the layer of material in spaced relation, and means extending from one of said members to the other and of such length as to place said enclosure and layer of absorbent material under tension whereby the window in said enclosure will be held in spaced relation with respect to said layer of absorbent material when the apparatus is in use, said means being separable from said members to permit the apparatus to'be collapsed for storage.

4. A method of distilling liquids when comprises the steps of supplying a liquid to be distilled to a layer of absorbent material exposing one face of said layer to solar radiation, con densing vapors issuing from the opposite face of said layer, and separating the resulting condensate from the liquid being distilled.

5. Collapsible solar distillation apparatus comprising a layer of flexible absorbent material presenting opposite liquid retaining faces, means for supplying liquid to be distilled to said layer, flexible means forming an enclosure extending about said layer, said enclosurehav'ing at least a portion thereof which is transparent and through which one face of said layer may be exposed to solar radiation, said enclosure including condenser surfaces supporting means moveable to an extended position for holding said enclosure and said layer in an operable position spaced relation wherein said enclosure is spaced from the opposite faces of said layer, said supporting means being movable to a collapsed position in which said enclosure and layer are foldable into a compact inoperative position, and collecting means separated from the liquid supplied to said layer and communicating with the space between said enclosure and both faces of said layer for receiving liquid condensing on the condenser surfaces of said enclosure when said supporting means is in said extended position.

6. Solar distillation apparatus comprising a collapsible fluid proof enclosure, presenting condensing surfaces a layer of absorbent material within said enclosure, means for supplying liquid to be distilled to said layer of absorbent material, a transparent flexible window in said enclosure, through which the heat of the sun may reach said layer of absorbent material means forminga dead air space in heat transferring relation between said window and one face of said layer of absorbent material, and means on the opposite side of said layer of absorbent material for receiving and separately collecting condensate formed on said condensing surfaces from vapors issuing from said layer.

7. Solar distillation apparatus comprising a layer of absorbent material presenting opposite liquid retaining faces, means for supplying liquid to be distilled to said layer, means forming a collapsible enclosure extending about said layer, said enclosure having at least a portion thereof which is transparent and through which one face of said layer may be exposed to solar radiation, and a portion which acts as a condenser means for holding said enclosure when not collapsed in spaced relation to the opposite faces of said'layer, and collecting means separated from the liquid supplied to said layer and communicating with the space between said enclosure and both faces of said layer for receiving liquid condensing on the condenser. surfaces of said enclosure.

WILLIAM R. P. DELANO. 

